4 ms·

For most cities, the cost of the water infrastructure (building and maintaining pipes) is much more expensive than the cost of the actual water. In Melbourne,

by nomilk 3y ago

For most cities, the cost of the water infrastructure (building and maintaining pipes) is much more expensive than the cost of the actual water. In Melbourne, Australia, since tap water mostly comes from catchments in national parks, water requires very little treatment (some fluoride and chlorine is added), so it works out cheap: ~$25 AUD per million liters. Desalinated water, by contrast, cost about 24 times more (~$600 AUD per million liters).

eikenberry 3y ago
Are you saying that the water is so cheap that switching to desalination will be a non-issue OR are you saying that this will make the water a large enough portion of the cost to make it significant?
- bsder 3y ago
  > Are you saying that the water is so cheap that switching to desalination will be a non-issue For human consumption: this is pretty much true. Desalinization works just fine for people. The biggest issue is where to put the extra salty waste products. When people talk about the "water crisis" in the US, for example, it's always about big agribusinesses doing farming.
  - genewitch 3y ago
    any time there's a fish storm in the atlantic, just dump the salt in that area?
  - yencabulator 3y ago
    > The biggest issue is where to put the extra salty waste products. The U.S. has "salt farms" where they evaporate water to produce salt. Sounds like colocating near the desalination plant would make those cheaper to operate.
grecy 3y ago
Melbourne is the perfect example of "what are we going to do when the water runs out". Remember when the storage was down to single digits?
- DoctorOetker 3y ago
  do you have a reference handy for this storage time series? from the historical net loss rate approaching the lows one can estimate the required backup desalination flow rate.
Ekaros 3y ago
Also here disposal of water cost nearly the same as water itself. 1,5€/m^3(water) vs 1,41€/m^3... And here it is sourced from artificially rained groundwater. So not most expensive way.
bcrosby95 3y ago
$600 AUD per million liters is still dirt cheap. That comes out to about an extra $3.5 per person per month (assumes 50 gallons of water/day/person). Would you be willing to pay an extra $3.5 per month to never have to worry about a drought again? I know I would.
- birdyrooster 3y ago
  Wouldn’t it make the cost of anything using power nearby more expensive too?
- nwiswell 3y ago
  > Would you be willing to pay an extra $3.5 per month to never have to worry about a drought again? Yes, you'll never have to worry about your basic supply of 50 gal/d/person being threatened in a drought, but just think about this for a second: the population of Melbourne is around 5 million people. In the 2020-2021 year, Melbourne Water delivered 439 billion liters (116 billion gallons) of fresh water[1]. That is roughly 318 million gallons of water consumption on an average day. What kind of drought would reduce the available water from 318 million gallons to 25 million gallons per day? Personal consumption (drinking, showering, household washing) is not the primary driver of water use. In general, it is dominated by agriculture, and to a lesser extent by industry. The economics of these activities would not permit an order of magnitude increase in the cost of fresh water. [1]: https://www.melbournewater.com.au/media/18976/download https://www.melbournewater.com.au/media/18976/download
  - Veserv 3y ago
    You missed a zero. 5 million people by 50 gallons/day is 250 million gallons/day. So they only missed by ~25%. Australia uses a estimated ~16T liters of water per year [1] for all uses including personal and agricultural. That is 16M ML * 600 AUD/ML for a total of ~10B AUD. Australia has a population of ~25M. So that is ~400 AUD/person to completely replace all water usage in Australia. As Australia is a island, I assume they do most of their own agriculture, so for additional 400 AUD on their food bill a year they never need to worry about a drought ever again. The Australian government appears to have a budget of ~500B/year which is around 25% of GDP [2]. So, for ~2% of the government budget or ~0.5% of GDP the economics are completely managed. [1] https://www.worldometers.info/water/ https://www.worldometers.info/water/ [2] https://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/pubs/rp/BudgetReview202021/AustralianGovernmentRevenue https://www.aph.gov.au/About_Parliament/Parliamentary_Depart...
golemiprague 3y ago
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by nomilk 3y ago

eikenberry 3y ago

Are you saying that the water is so cheap that switching to desalination will be a non-issue OR are you saying that this will make the water a large enough portion of the cost to make it significant?

bsder 3y ago
> Are you saying that the water is so cheap that switching to desalination will be a non-issue For human consumption: this is pretty much true. Desalinization works just fine for people. The biggest issue is where to put the extra salty waste products. When people talk about the "water crisis" in the US, for example, it's always about big agribusinesses doing farming.
- genewitch 3y ago
  any time there's a fish storm in the atlantic, just dump the salt in that area?
- yencabulator 3y ago
  > The biggest issue is where to put the extra salty waste products. The U.S. has "salt farms" where they evaporate water to produce salt. Sounds like colocating near the desalination plant would make those cheaper to operate.

grecy 3y ago

Melbourne is the perfect example of "what are we going to do when the water runs out". Remember when the storage was down to single digits?

DoctorOetker 3y ago
do you have a reference handy for this storage time series? from the historical net loss rate approaching the lows one can estimate the required backup desalination flow rate.

Ekaros 3y ago

Also here disposal of water cost nearly the same as water itself. 1,5€/m^3(water) vs 1,41€/m^3... And here it is sourced from artificially rained groundwater. So not most expensive way.

bcrosby95 3y ago

$600 AUD per million liters is still dirt cheap. That comes out to about an extra $3.5 per person per month (assumes 50 gallons of water/day/person). Would you be willing to pay an extra $3.5 per month to never have to worry about a drought again? I know I would.

birdyrooster 3y ago
Wouldn’t it make the cost of anything using power nearby more expensive too?
nwiswell 3y ago
> Would you be willing to pay an extra $3.5 per month to never have to worry about a drought again? Yes, you'll never have to worry about your basic supply of 50 gal/d/person being threatened in a drought, but just think about this for a second: the population of Melbourne is around 5 million people. In the 2020-2021 year, Melbourne Water delivered 439 billion liters (116 billion gallons) of fresh water[1]. That is roughly 318 million gallons of water consumption on an average day. What kind of drought would reduce the available water from 318 million gallons to 25 million gallons per day? Personal consumption (drinking, showering, household washing) is not the primary driver of water use. In general, it is dominated by agriculture, and to a lesser extent by industry. The economics of these activities would not permit an order of magnitude increase in the cost of fresh water. [1]: https://www.melbournewater.com.au/media/18976/download https://www.melbournewater.com.au/media/18976/download
- Veserv 3y ago
  You missed a zero. 5 million people by 50 gallons/day is 250 million gallons/day. So they only missed by ~25%. Australia uses a estimated ~16T liters of water per year [1] for all uses including personal and agricultural. That is 16M ML * 600 AUD/ML for a total of ~10B AUD. Australia has a population of ~25M. So that is ~400 AUD/person to completely replace all water usage in Australia. As Australia is a island, I assume they do most of their own agriculture, so for additional 400 AUD on their food bill a year they never need to worry about a drought ever again. The Australian government appears to have a budget of ~500B/year which is around 25% of GDP [2]. So, for ~2% of the government budget or ~0.5% of GDP the economics are completely managed. [1] https://www.worldometers.info/water/ https://www.worldometers.info/water/ [2] https://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/pubs/rp/BudgetReview202021/AustralianGovernmentRevenue https://www.aph.gov.au/About_Parliament/Parliamentary_Depart...

golemiprague 3y ago

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